Socket adapter



Jan. 12, 1965 J. R. Ruocco 3,

SOCKET ADAPTER 2 Sheets-Sheet 1 Filed Aug. g 21 1962 JOSEPH RUB/N0 RUOCOO INVENTOR.

Jan. 12, 1965 J. R. RUOCCO 3,165,371

SOCKET ADAPTER Filed Aug. 21, 1962 2 Sheets-Sheet 2 JOSEPH RUB/N0 RUOOGO INVENTOR.

United States Patent 3,165,371 1 SECRET ADAPTER Joseph Rubino Ruocco, 39 3rd Ave. E., Newark, NJ. Filed Aug. 21, 1962, Ser. No. 218,417 9 Claims. Cl. 339-154) This invention relates to a socket adapter and more particularly to an adapter for use in an electrical socket in order to adapt the particular socket for use with a lamp bulb of a different size than that for which the socket was designed.

Although a socket adapter made in accordance with this invention has general utility in the electrical field, it is particularly useful in connection with photoflash lamps employed in the art of photography.

Although certain modern flash guns are provided with what may be termed a universal socket, that is, a socket constructed for operation with flash bulbs of various sizes and base constructions, such universal sockets are of complex construction adding significantly to the purchase price of the device. The majority of flash guns presently sold, and those sold before the advent of the universal socket, are provided with a socket which is designed to receive a particular flash bulb. In many instances, the user finds it necessary or desirable to use bulbs of a different size. Specifically, the owner of a flash gun having a relatively large socket may desire to use one of the recently-developed flash bulbs which is smaller than those heretofore available. Conversely, the owner of a flash gun having a relatively small socket may wish to use a flash bulb of larger size in order to increase scene illumination or to use light of a different color composition. This necessitates carrying two flash guns.

Accordingly, the principal object of this invention is the provision of an adapter for an electrical socket which can be used quickly and effectively to condition the socket for use with a bulb of a size different from that for which the socket has been designed.

Another object of this invention is the provision of a socket adapter which is of simple construction and positive operation.

A further object of this invention is the provision of a socket adapter which can be used, in one or another manner, to accommodate bulbs which, respectively, are larger or smaller than the particular bulb for which the particular socket has been designed.

A still further object of the invention is the provision of a socket adapter for use in connection with sockets of various constructions thereby to adapt the socket for operation With either a bulb of a different size or a bulb having a different base.

These and other objects and advantages will become apparent from the following description when taken with the accompanying drawings. It will be understood, however, that the drawings are for purposes of illustration and are not to be construed as defining the scope or limits of the invention, reference being had for the latter purpose to the claims appended hereto.

In the drawings wherein like reference characters denote like parts in the several views:

FIGURE 1 is a side view showing a socket adapter made in accordance with this invention, together with a flash bulb and the reflector of a flash gun;

FIGURE 2 is a top view of the socket adapter drawn to a larger scale;

FIGURE 3 is a cross-sectional view taken along the line III-III of FIGURE 2;

FIGURE 4 is an isometric view showing the assembly of the center contact;

FIGURE 5 shows a modern, all-glass flush bulb;

FIGURE 6 is a fragmentary, isometric view drawn to ICC an enlarged scale and showing a more universal construction of the center contact;

FIGURE 7 is an isometric view showing a clip for use with such center contact to condition the socket adapter for accommodation of an all-glass flash bulb; and

FIGURE 8 is a fragmentary, isometric view showing the clip attached to the center contact.

Reference is first made to FIGURE 1, wherein there is shown a screw-type, or threaded, socket 10 carried by a reflector 11. Such socket normally is designed to receive a flash bulb which has a smaller base diameter than the illustrated bulb 12. The socket adapter 13 comprises a bowl-like body 14, differing in diameter at opposite ends, with four integral prongs 15 extending from the top and four integral prongs 16 extending from the bottom and lying on circles of diameters generally corresponding with the diameters of the body ends from which they extend. The body and prongs are made of a suitable spring material and each of the prongs is folded, or reversely-creased along transverse lines whereby each prong is relatively rigid, yet, can be flexed inwardly or outwardly relative to the body axis.

Although each prong is reversely-folded, it preferably is generally convex about its vertical axis, as shown in FIGURE 2, thereby facilitating the attachment of the adapter either to the socket or the lamp. As illustrated in FIGURE 1, the bulb 12 has a base diameter largerthan that of the socket 10. In such case, the lower prongs 16 of the adapter are inserted, axially, into the socket thereby forming a good mechanical and electrical contact therewith. With the adapter so attached to the socket, the base of bulb 12 can be pressed, axially, between the four upper prongs 15 which lie on a diameter larger than that of the lower prongs 16. On the other hand, assuming the socket 10 is of a larger size to receive directly the bulb l2 and it is desired to use a bulb with a smaller base diameter, the adapter is inverted, the prongs 15 inserted into the socket and the bulb inserted between the now-upper prongs 16. It can also be seen that if the socket 10 is to be used with a bulb of smaller diameter, the larger-diameter prongs 15 can be inserted over the socket thereby en gaging the outer socket wall. In a reverse sense, if the socket 10 is of smaller diameter than that shown, the smaller-diameter adapter prongs 16 can be inserted over the socket. It will be apparent that a socket adapter of a given size and constructed as shown (having two sets of generally axially-extending prongs lying on circles of two different diameters and the free end portions of which are deflectable toward or away from the adapter axis) can be used to establish electrical contact with the socket by axially inserting one or the other of the sets of prongs into or over the socket shell. Such construction also renders the adapter useful for attachment to sockets of types other than the screw-type socket illustrated in the drawing, specifically, bayonet-type sockets and the new ejector type socket having a circumferential groove formed in the shell.

As shown schematically in FIGURE 1, the electrical circuit between a battery 17 and the bulb (disposed within the socket) is completed upon closure of a switch 18 actuated by the cam-era shutter mechanism, one battery terminal being connected to the socket shell and the other to a center contact 19 disposed centrally of the socket base. When the adapter is attached to the socket, electrical continuity between the center socket contact 19 and the center bulb contact 20 is established by means of a vertically-disposed strip 21, made of suitable conducting material such as, for example, Phosphor bronze (see FIGURE 2), which is supported within the shell and electrically insulated therefrom by a rod 22 of insulating material.

The assembly of the center contact strip 21 and the Patented Jan. 12, 1965 into the other body opening.

URE 2. The adapter'body 14 is provided with dia-- metrically-opposed rectangular openings for snugly re- In the assembly ceiVing-the ends 27 of the rod 22. operation, one rod end is passed through the associated body' opening, after which the other rod end is slidably moved along the inner wall of the body 14 until itsnaps Inasmuch as the adapter is a relatively thin-walled member made of suitable spring material, such as Phosphor. bronze, thedescribed insertion of the rod to the illustrated, operative position is efiected quite readily without permanent deformation of the bowlshaped body; The disposition of the rectangular ends 27, of the rod 22, within the rectangular openings formed in the body wall, prevents rotation of the rod and the resulting rod shoulders prevent axial movement thereof, whereby the center contact strip .21 remains at all times centrally disposed within thebody.

In the assembled adapter, the free ends 25 and 26, of-

the center contact strip 21, are disposed in planes recessed from the free ends of the associated prongs l and 16,

respectively. When the adapter is attached to a socket,

one of the ends (25 or 26) compressively abuts against the center contact of the socket. Similarly, when a bulb is inserted into the adapter, the center contact of the bulb compressively abuts against the other strip end.

It is pointed out that the outer surfaces of the two bends formed in each prong (identified by the letters a and b in FIGURE 3) have a common radius whereas the free end 6 of each prong terminates along a radial line greater than the inner bend d. Thus, when the prongs are axially inserted into a socket, two bends, or threads, of each prong engage the cooperating socket threads. However, when a bulb is inserted between the prongs, the base thereof is engaged by only a single thread of each prong. Consequently, the bulb, after use, can'be removed from the adapter while the adapter remains afiiixed to the socket.

There have recently been made available all-glass flash bulbs generally referred to as type AG bulbs. As shown in FIGURE 5, such'bulbs do not have a metal base. The inner filament, or ignition wires 30, 31, have ends passing through the generally rectangular' base portion 32, the end of the wire 30 being bent into a loop 33 along the front surface of the base portion and the end of the wire 31 being formed into a loop 34 along the rear surface of the base portion. Sockets which are designed for use with lamps of this type include separate contact members for completing the circuit between the battery and the two loops 33, 34.

URE 1) is inserted into the 36 from the similar ledge portions 35'- and 36' (see'FlG- URE 6) has an integral stem 44 extending therefrom and.

an integral, inwardly-directed tab 45 formed at the for- Ward end of the arcuate portion l'2; It is here pointed ledge portion 36. This properly positionsthe clip.

By modifying the free end of the center contact strip, a

socket adapter made in accordance with this invention can be conditioned for use either with lamps having a conventional metal base or the all-glass type. The modified form of the contact strip is shown in the fragmentary,

isometric view of FIGURE 6, to which reference now is made.

The free end of the axially-compressible end 25 (of the center contact strip 21) is formed to provide a generally rectangular ledge portion 35 separated from a similar ledge portion 36 by a channel 37. Preferably, a thin,

transverse slot 38 is cut through the ledge portions,

out that the thickness of the clip to is exaggerated in the drawings.

tact strip and slides the clip along'the supporting ledges 35, 36 until the clip tab45 engages the forward end of the will be noted that the width of the clip is somewhat less than that of the supporting ledges 35 and 36, thereby eliminating any possibility of the electrical continuity between the clip and the ledge portions 35 and 36'. Since the clip is made of thin material, its insertion into position onthe center contact strip results in a relatively minor amount of spreading of the channel 37 but such spreading is not transmitted to that portionof the channel lying between the ledge portions 35, 36' becaus of the transverseslot 38. a

With the clip attached to the center contact strip, the base of theall-glass bulb can be inserted into. the adapter,

whereby one Wire loop of the lamp will be in electrical.

contact with either of the ledge portions 35' or 36 and the other wire loop of the lamp will be in electrical contact with the clip. The depth of the channel 37 is made to accommodateall, or most of, the base portion of the lamp and the channel widthis somewhat less than that of the lamp base portion, all for the purpose of retaining the lamp in operative position.

The stem 44, of the clip, has a length such that the free end thereof engages one of theprongs of the adapter (such as the rear prong 15 visible in FIGURE 3) when the clip is attached to the center contact strip. When the prong Walls are arcuate, as described above, the end of the clip stem is also of corresponding arcuate form, thereby providing a substantial area of surface contact to assure electrical continuity between the clip and the prong. Thus, one side of the battery is connected to one of the'wire loops of the lamp through the center contact strip, whereas the other side of the battery is connected to the other wire loop of the lamp through the body of the adapter, a prong and the clip.

Both ends of the center contact strip can be formed as shown in FIGURE 6. Alternatively, one end only need be so formed and the user-can readily reverse the center contact strip within the adapter body, if necessary, upon specific occasions. Such reversal of the center contact strip is quite simple, as the strip is assembled to the adapter body by snapping the ends of the rectangular insulator strip 22 into the holes provided in the body. a

Having now described the invention, various changes and modifications will become apparent to those skilled in this art. It is preferable to form' the. individual FIGURE 7, which'is an' Actually, the clip is very thin so that it can .be snapped into position over the ledge portions 35 and 36, as shown in FIGURES, with the rectangular clip portion 41' snugly embracing the rectangular ledge por-- adapter prongs along a circle that is concentric with the body axis in order to provide individual prongs of maximum width which, at the same time, can be axially pressed into a socket without requiring an excessive force. However, when the individual prongs are relatively narrow, they can be formed so that each prong lies in a single plane. The number and length of the prongs can be varied to meet specific requirements. Also, the flat, center contact strip 21 may be replaced by a simple coiled spring. It is contemplated that these and similar changes and modifications can be made without departing from the scope and spirit of the invention as recited in the following claims.

I claim:

1. A socket adapter comprising a unitary, bowl-shaped body portion, differing in diameter at opposite ends, having a plurality of peripherally-spaced prong members extending axially of the body portion and from each end thereof; the prong members at one end lying on a circle of diameter different from that on which those at the other end lie, generally corresponding with the differing diameters of the body ends, a center contact member disposed axially within the said body portion, and insulating means supporting the said contact member in fixed position within the body portion.

2. The invention as recited in claim 1, wherein each of the said prong members are reversely bent along transverse lines.

3. The invention as recited in claim 1, wherein the said center contact member includes axially-compressible free ends and the said insulator means comprises a rod member having ends extending through diametricallyopposed openings formed in the Wall of said body portion.

4. The invention as recited in claim 1, wherein the center contact member has an axially-compressible end terminating in laterally-spaced ledge portions forming a longitudinal channel therebetween.

5. The invention as recited in claim 4, in combination with a clip member removably attachable to the 6 said spaced ledge portions, said clip member having an integral stem extending therefrom and said clip member having an insulating coating thereon for the purpose of electrically insulating the clip member from the center contact member.

6. A socket adapter comprising,

(a) a bowl-shaped body,

(b) a first set of peripherally-spaced, resilient prong members extending axially from one end of the body, said prong members lying substantially on a circle of one diameter,

(0) a second set of peripherally-spaced, resilient prong members extending axially from the opposite end of the body, said prong members lying substantially on a circle of another diameter,

(d) a center contact member axially positioned within the body, said contact member having axially-compressible free ends, and

(e) an insulator rod secured to the said center contact member and having ends passing through openings formed in the said body.

7. The invention as recited in claim 6, wherein each References Cited in the file of this patent UNITED STATES PATENTS Harris et al. Sept. 4, 1917 Dominick May 10, 1927 

1. A SOCKET ADAPTER COMPRISING A UNITARY, BOWL-SHAPED BODY PORTION, DIFFERING IN DIAMETER AT OPPOSITE ENDS, HAVING A PLURALITY OF PERIPHERALLY-SPACED PRONG MEMBERS EXTENDING AXIALLY OF THE BODY PORTION AND FROM EACH END THEREOF; THE PRONG MEMBERS AT ONE END LYING ON A CIRCLE OF DIAMETER DIFFERENT FROM THAT ON WHICH THOSE AT THE OTHER END LIE, GENERALLY CORRESPONDING WITH THE DIFFERING DIAMETERS OF THE BODY ENDS, A CENTER CONTACT MEMBER DISPOSED AXIALLY WITHIN THE SAID BODY PORTION, AND INSULATING MEANS SUPPORTING THE SAID CONTACT MEMBER IN FIXED POSITION WITHIN THE BODY PORTION. 